This invention relates generally to devices and techniques for plugging flow holes. More particularly, the present invention relates generally to devices and techniques for plugging the flow holes of the core support barrel of a nuclear reactor.
In some nuclear installations, fuel rod wear has been directly associated with the characteristics of the flow path through the reactor core. For example, it has been established that baffle jetting causes fuel rod wear under certain conditions. In some installations, the flow characteristics can be suitably modified to alleviate the wear to the fuel rod by modifying the reactor core flow path to an upflow-type core flow path. In order to implement the flow modification, it is necessary that existing core barrel flow holes be plugged. In some reactor designs, this may require the plugging of 16 angularly spaced core barrel flow holes. Moreover, the flow holes to be plugged are typically positioned below the level of the adjacent surrounding thermal shield, and thus the thermal shield may present a significant obstacle to the hole plugging process.